Wellhead leak containment and blowout deflection apparatus

ABSTRACT

A containment apparatus is provided for containing fluids, such as oil and salt water leaking from a wellhead, and storing such fluids for re-use or disposal. The apparatus is capable of quick installation without interfering with wellhead operation, and requires few if any tools.

FIELD OF THE INVENTION

[0001] The present invention relates to servicing equipment for oilwells generally, and in particular relates to a means of containingfluids, such as oil and salt water, leaking from a wellhead, and storingsuch fluids for further use.

BACKGROUND OF THE INVENTION

[0002] An environmental and economic problem at oil and gas wellsites isthe leakage of oil and/or other produced fluids, such as salt water andrelated oil by-products. Typically, the seals in a suffing box of awellhead pumped by a pumpjack wear out over time and begin to leak oildown the wellhead and into the surrounding soil before the leak isdetected and new seals are installed. This pattern may repeat itselfmany times over the life of a wellsite, resulting in contamination ofthe wellsite with oil and produced fluids. Such contamination can resultin water table damage and may spread to residential water wells and thelike. Reclamation costs of such wellsites are time consuming andexpensive. Some earlier attempts have been made to address such leaks,but have failed, partly because, until recently, the scope of theproblem has either not been know or not taken very seriously.

[0003] Some of the earlier attempted solutions to the problem havefailed because of ineffective sealing at the lower flange of thestuffing box, thus allowing the oil and/or produced fluid to leak out ofthe fluid containment device along the wellhead piping onto thesurrounding soil. Other products have not been adopted as they requiredisruption of the oilwell operation for their installation, and someeven require modification to the stuffing box and/or wellhead piping andcomponents. Another drawback is that such prior products requireconsiderable time (one or more hours) and tooling for installation.

[0004] What is therefore desired is a product that overcomes thesedisadvantages and problems.

SUMMARY OF THE PRESENT INVENTION

[0005] According to the present invention, there is provided in oneaspect an apparatus for containing fluids, such as oil and salt waterleaking from a wellhead, and storing such fluids for re-use or disposal.The apparatus should be capable of quick installation withoutinterfering with wellhead operation, and should require few if anytools.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0006] Embodiments of the invention will now be described, by way ofexample only, with reference to the accompanying drawings, wherein:

[0007]FIG. 1 is a side view, partially broken away, of a containmentapparatus according to a preferred embodiment of the present inventionmounted on a stuffing box of a wellhead for capturing any fluids leakingfrom the stuffing box, and for chanelling and storing the leaked fluidsfor further use;

[0008]FIG. 2 is a top perspective view of a base portion of thecontainment apparatus of FIG. 1;

[0009]FIG. 3 is a top plan view of the base of FIG. 2;

[0010]FIG. 4 is a cross-sectional view of the base along line 4-4 ofFIG. 3;

[0011]FIG. 5 is a cross-sectional view of a drain hole portion of thebase along a line 5-5 of FIG. 3;

[0012]FIG. 6 shows a gasket for placing along a split section of thebase of FIG. 1;

[0013]FIG. 7 is a bottom perspective view of a an alternate embodimentof the containment apparatus of FIG. 1 showing an adaptor ring formounting the base to a different sized stuffing box;

[0014]FIG. 8 is a top plan view of a cover portion of the containmentapparatus;

[0015]FIG. 9 is an elevated side view of the cover of FIG. 8;

[0016]FIG. 10 is a cross-sectional view of the cover along line 10-10 ofFIG. 9;

[0017]FIG. 10a is a perspective view of a split slinger disk formounting onto a sucker rod beneath the cover;

[0018]FIG. 11 is an elevated view of an alternate embodiment of a coverof the containment apparatus; and,

[0019]FIG. 12 is a side view of the alternate embodiment of the coverviewed in the direction of arrow 12 in FIG. 11.

LIST OF REFERENCE NUMBERS IN DRAWINGS

[0020]20 wellhead

[0021]22 sucker rod

[0022]24 stuffing box

[0023]26 flange of 24

[0024]30 containment apparatus

[0025]40 base of 30

[0026]42 sidewall

[0027]43 lip of 42

[0028]44 top end (open)

[0029]46 bottom end (open)

[0030]48 upturned lip

[0031]50 reservoir

[0032]52 tabs

[0033]53 buckle for 30

[0034]54 split of 40

[0035]56 flange of 40

[0036]58 gasket

[0037]60 flange(s) of 58

[0038]62 web of 58

[0039]64 drain

[0040]66 hose

[0041]68 collection tank

[0042]70 lid

[0043]72 lower lip

[0044]73 lower opening of 70

[0045]74 flange of 70

[0046]76 apertures in 74

[0047]78 wing nuts

[0048]79 hinge pin and lanyard arrangement

[0049]80 opening in top of 70

[0050]82 split disc

[0051]84 extended top of alternate embodiment of lid

[0052]90 adaptor assembly

[0053]92 split adaptor disk

[0054]94 seal and hose clamp

DESCRIPTION OF PREFERRED EMBODIMENTS

[0055] The figures show an apparatus (generally designated by referencenumeral 30) for containing fluid leaks from a wellhead 20. A pumpjacktypically moves, or lifts, a vertically oriented polished rod 22 up anddown in the wellhead to pump underground fluids to surface. The polishedrod passes through a stuffing box 24 at the upper end of the wellheadwhich is meant to seal the wellbore from the ambient. However, as theseals in the stuffing box wear out, fluids often penetrate the seals andescape onto the ground surrounding the wellhead. Hence, the presentapparatus 30 is mounted aboveground around the wellhead's stuffing box24 and where such leaks often occur. The leaking “fluids” referred toherein are most commonly crude oil and salt water, and can include anyother liquids toxic to the surrounding environment.

[0056] The wellhead apparatus 30, referred to herein soemtimes as aSKIRT™, is principally composed of a base 40 and a two-piece cover 70.Referring first to the base 40, and FIGS. 1-6, a vertically orientedcircumferential sidewall 42 forms a basin with an open first, or top,end 44 and an open bottom end 46. The opposed second, or bottom, end hasan upturned lip 48 forming a circumferential reservoir 50 below thebottom opening 46 for capturing leaking fluids. The reservoir is animportant feature in that it forms a means of capturing the leakingfluid away from the opening 46 to reduce the chances of escapetherethrough. Rather, the reservoir's floor has a drain 64 (good resultshave been had with a drain opening of 2 inch nominal diameter) fordraining the fluid from the reservoir through a detachable flexible hose66 to a grounded heavy-duty fluid collection tank 68 from which thefluid may be recovered periodically for further use or disposal.

[0057] Several integral tabs 52 extending radially inwardly from theupper edge of the lip 48 are adapted to engage a bottom flange 26 of thecommon single or multi-staged stuffing box, and thus serve to supportthe base on the wellhead. The base is split at 54 to allow quickmounting of the base onto the wellhead without disruption of pump jackoperation. Hence the material forming the base, such as a plastic,should be flexible enough to allow the base to be pried opensufficiently to pass over the polished rod and other components abovethe stuffing box. Each side of the split area 54 has opposed inwardlyextending flanges 56 to avoid fluidleakage out of the reservoir 50through the split 54.

[0058] A compressible rubber or neoprene gasket 58 (see FIG. 6) isprovided to fluidly seal the base and the flange beneath the stuffingbox. The gasket 58 is contoured to generally reflect the cross-sectionalshape of the base (as viewed in FIG. 4). Each gasket flange 60 is shapedto mate with a respective base flange 56 to prevent fluid leakage out ofthe base 40 through the split 54, and the gasket's web 62 is adapted tofollow the perimeter of the upturned lip 48 and to engage the flange ofthe stuffing box to fluidly seal the base about the stuffing box. Oncethe base 40 and the gasket 58 are properly located about the stuffingbox, a lockable latching buckle 53 tightens, or “closes”, the base andgasket to the stuffing box's flange in a friction fit.

[0059] As the size of stuffing boxes is not uniform, the base's bottomopening 46 may be too large for certain boxes. Hence, an adaptorassembly 90 (shown in FIG. 7) is provided to secure the base 40 beneaththe stuffing box. The assembly includes a donut-shaped split adaptordisk 92 (resembling the shape of the split slinger disk shown in FIG.10a) made of a suitable flexible and resilient material which may bepried open and slipped onto the piping below the stuffing box. The disk92 should be secured immediately below the stuffing box, such as with acircumferential seal and hose clamp 94 (or like arrangement). The outerdiameter of the disk is sized so that the base's tabs 52 rest thereon,thereby supporting the base about the stuffing box. The mounting of theadaptor assembly may therefore be achieved without interfering with thewell's operation.

[0060] The base 30 is capped by a detachable two-piece cover or lid 70.One half of the lid is shown in FIGS. 7-10, and the other half whichabuts the one shown is in essence a mirror image of the one shown. Thelid is split in two so that it may be mounted about the stuffing box andsucker rod without disrupting wellhead operation. The lid has anoutwardly and downwardly flared circumferential lip 72 forming a first,or lower, opening 73. The perimeter of the lip is shaped to mate atopthe outwardly and upwardly flared lip 43 of the base 40. The transverseedge 74 of each lid portion is formed by a flange with several spacedapertures 76 for bolting the cover sections together, preferrably byhand without tools, such as with finger-operated wing nuts 78 (FIG. 7).The assembled cover is in turn securedto the base 40, such as with twoor more hinge pin and lanyard arrangements 79 (FIG. 7). The upper andlower lips 72, 43 are adapted to mate in fluid sealing manner, namelyany fluid that might impact the domed inside surface of the lidprogresses down the inside surface and flows across the cover/baseinterface toward the base's reservoir 50 rather than escaping to theambient.

[0061] The dome of the cover has a second, upper opening 80 sized forfitting about the sucker rod 22, and a split slinger disc 82 (shown inFIG. 10a) made of high density polyethelene is fitted about the suckerrod 22. The lid surrounds and covers the stuffing box body to functionas a blow-out deflector and weather protector. In the event of ablow-out the disc 82 is forced to slide upwardly along the rod to sealthe opening 80, and so fluids escaping as a result of the blow-outdeflects off the lid and settles in the base, thus being contained byapparatus 30.

[0062] The operation and many advantages and features of the presentinvention may now be better understood and summarized.

[0063] Good results have been achieved for the base and lid constructionusing flexible lightweight plastic materials adapted for either standard(i.e. down to −50 C ambient) or high temperature (up to 122 C)applications. The standard temperature wellhead Skirt design allows forinstallation on conventional oil pumping operations, whereas the hightemperature wellhead Skirt design allows for installation on hightemperature heavy oil pumping operations.

[0064] The present containment apparatus 30 installs easily and quicklyabout a stuffing box and can be installed without shutting down pumpingoperation.

[0065] No special tools are required, thus facilitating Skirtinstallation.

[0066] The Skirt does not utilize replaceable absorbent materials. Anyleakage is drained through a the drain hole 64 in the base into thelarge grounded heavy-duty fluid collection tank. This allows forrecycling of leaked fluid back to the battery and prevents any groundcontamination due to a packing blowout. Prior art devices are notadapted to contain excessive leakage.

[0067] The base 40 has four integrated mounting tabs 52 and acompressible rubber or neoprene gasket 58 for quick and convenientsupport on the lower flange of the stuffing box (or on the adaptorassembly 90). Further, the base 40 is split, allowing for installationwithout disruptions in wellhead operations.

[0068] The Skirt is closed and secured to the stuffing box with thelockable latching buckle 53 located on the outer face of the base. Whenlatched, the split in the base is sealed with the compressible rubber orneoprene gasket 58 located below the four integrated tabs 52.

[0069] The two sections of the lid 70 fit over the base 40 and bolttogether via six hand tightened wing nuts, thus allowing for ease ofinstallation without interruptions in pumping operations.

[0070] The lid is secured to the base by two locking pin and lanyardarrangements located opposite to each other on each half of the lid. Thelid sections are placed over the base and the pins are placed throughaligned pre-drilled holes in the lid and base to secure the lid to thebase. Such arrangement provides ease of access to the stuffing box forwellhead maintenance.

[0071] Once the base 40 is installed on the wellhead, it need not beremoved for maintenance of the stuffing box since removal of the lidprovides sufficient unobstructed access to the stuffing box.

[0072] The completely assembled containment apparatus 30 also functionsas a blowout deflector to further reduce the risk of ground and watercontamination by escaping fluids.

[0073] The Skirt protects the stuffing box seals from damage by snow,wind and sand.

[0074] The Skirt controls against wellhead freeze up and wax problems,and helps deter wellhead surface casing rust and corrosion.

[0075] The Skirt reduces or eliminates ground and water contaminationfrom the stuffing box, thus reducing costly land reclamation and wellabandonment costs due to excessive wellhead leakage.

[0076] The Skirt reduces costly wellhead steam cleaning.

[0077] The reservoir 50 avoids leakage of fluid from the base around therod or through the base's bottom opening 46.

[0078] In one variation of the lid, an elongated or extended top portion84 (see FIGS. 11 and 12) is provided to fit over and surround apollution box flapper valve used above the stuffing box.

[0079] In yet another variation of the present invention one or bothhalves of the lid may be constructed of a clear UV protected plexi-glassmaterial to allow the operator a convenient, unobstructed view into thebase.

[0080] Installation of the Skirt requires no expensive modifications tothe wellhead, moving of equipment, valves, or removal of the Presco(line pressure) switch.

[0081] The Skirt may be used on all types of rod pump oil wells,including wells with Rodaflex™ pumping units, and allows forinstallation and use of polish rod lubricators.

[0082] The above description is intended in an illustrative rather thana restrictive sense, and variations to the specific configurationsdescribed may be apparent to skilled persons in adapting the presentinvention to other specific applications. Such variations are intendedto form part of the present invention insofar as they are within thespirit and scope of the claims below.

I claim:
 1. An apparatus comprising a reservoir means for containingfluids leaking from a wellhead, and storing such fluids for re-use ordisposal.